1. Field
The present invention relates to a pixel, a display device including the same, and a driving method thereof.
2. Description of the Related Art
Cathode ray tubes (CRTs) have been used to display images. However, CRTs can have the disadvantages of being heavy and large in size. Currently, various flat panel displays are being developed that can reduce the heavy weight and large volume that are drawbacks of CRTs. Examples of flat panel displays include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic light emitting diode (OLED) displays.
OLED displays can display images using OLEDs that generate light by recombination of electrons and holes. An OLED display can have a fast response speed, can be driven with low power consumption, and can have the advantages of improved (or excellent) luminous efficiency, luminance, and viewing angle.
Generally, OLED displays can be classified into two types according to the driving method of the OLED display: passive matrix OLEDs (PMOLEDs) and active matrix OLEDs (AMOLEDs).
Of the two types, the active matrix OLED display in which unit pixels are selectively lit is primarily used because of its good resolution, contrast, and operation speed.
One pixel of an active matrix OLED display may include an OLED, a driving transistor for controlling an amount of current supplied to the OLED, and a switching transistor for transmitting a data signal to the driving transistor to control an amount of light emitted by the OLED.
Recently, research has been underway on a compensation circuit to compensate for a threshold voltage variation (or deviation) of the driving transistor included in the pixel of the active matrix OLED display. However, when the compensation circuit is used to display an image at a desired luminance, the response speed of the pixel varies according to an increase/decrease in a data voltage applied to the driving transistor, due to hysteresis, such that it is difficult to correctly display gray levels. For example, a delay in response speed may be generated when driving the OLED display to express a luminance from black to white, and this problem may cause sticking when scrolling text on a screen.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.